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1
Content available remote Mathematical model decomposition of gas hydrates
EN
The article presents the results of the study of the influence of pressure and temperature of the gas-water environment on the process of hydrocarbon gas hydration formation, occurring on its phase interface surface. A mathematical model is proposed to determine the optimum ratios of pressure, gas temperatures, water, and gas bubble sizes in the bubbling, gas ejection, or mixing processes. It was determined that there is a gas temperature range where the hydrate formation speed is maximum. The research findings can be used to optimize various technological processes associated with production of gas hydrates in the industry.
EN
For the hydrate synthesis technology intensification, the study of mass transfer processes at the interfacial surface is important. In the article experimental setup and the results of field experiments to determine the mass transfer processes dynamics that occur during the propane hydrate synthesis are presented. Scientific novelty is to establish the quantitative characteristics of the time influence on the mass transfer processes intensity at the interfacial surface in the gas hydrates existence conditions. Based on the experimental studies results, the mass transfer comparison in the hydrate formation area and beyond it has been made. The practical significance of the research results is to determine the quantitative indicators of the mass transfer processes rate in the conditions of propane hydrate formation. The work results can be used to design equipment for the gas hydrates synthesis.
EN
Located in Southeast Asia, Vietnam has a diverse and complex geology. Seismic methods have solved many different geological tasks such as interpreting geological structure, petroleum and mineral exploration, research gas hydrate, etc. In this report, we present some achievements using Seismic methods for petroleum exploration to find not only structural traps but also stratigraphic traps in sedimentary basins, in non-traditional fractured granite basement reservoirs, and in the initial stage of gas -hydrate exploration. Seismic acquisition methods such as 3D / 4C have been applied effectively. Advanced seismic processing and interpretation methods have been used, such as applying seismic filters (T-P, Radon, SRMA…), seismic imaging (Pre-stack Migration/PSTM, Control Beam Migration/CBM), Seismic Inversion (SI), Amplitude Versus Offset Analysis (AVO), Seismic Sequence Stratigraphy, Seismic Attributies, Artificial Neural Network (ANN), etc. The results seismic interpretation, thereby which lead to enhansed effectiveness of oil and gas exploration programs.
PL
Położony w Azji Południowo-Wschodniej Wietnam ma różnorodną i złożoną geologię. Metodami sejsmicznymi rozwiązano wiele różnych zadań geologicznych, takich jak interpretacja struktury geologicznej, poszukiwania ropy naftowej i minerałów, hydratów gazu itp. W niniejszym artykule przedstawiono niektóre osiągnięcia w których wykorzystano metody sejsmiczne do poszukiwań ropy naftowej, w celu określenia zaburzeń strukturalnych, a także stratygraficznych w basenach osadowych, w nietradycyjnych zbiornikach granitowych oraz w początkowej fazie eksploracji gazu i hydratów. Skutecznie zastosowano metody akwizycji sejsmicznej 3D/4C. Zastosowano zaawansowane metody przetwarzania i interpretacji danych sejsmicznych, takie jak stosowanie filtrów sejsmicznych (TP, Radon, SRMA), obrazowanie sejsmiczne (Migracja / PSTM, Migracja wiązki kontrolnej / CBM), Inwersja sejsmiczna (SI), Amplituda kontra przesunięcie (AVO), stratygrafia sekwencji sejsmicznych, atrybuty sejsmiczne, sztuczna sieć neuronowa (ANN) itp. Wyniki interpretacji sejsmicznej pozwalają na osiągnięcie zwiększonej skuteczności programów poszukiwania ropy i gazu.
4
Content available remote Main features of gas hydrates
EN
Natural gas hydrates are specific combinations of two very common substances: water and natural gas. If these substances come into contact at high pressure and low temperature, the solid mass is formed, similar to ice. Huge amounts of hydrate deposits are found in the seabed of the ocean floor and in the polar zones, where they are kept in the thermobaric conditions that permit formation of gas hydrates. Synonymous with the term "hydrate" are gas hydrates, methane hydrates, or clathrates (from the Greek "frame"). The basic structural element of hydrates is crystal lattice of water molecules, inside of which gas molecules are located. Hydrate structure is similar to the structure of ice, but differs from the latter by the fact that gas molecules are located inside the crystal cells rather than between them. Outside hydrates are looking like ice, although they can be seen not frequently. They do not behave like ice. If a match is brought to them, they flash. When conventional hydrocarbon reserves can not provide energy to the growing economy and population, then they will be substituted with the so-called unconventional hydrocarbon reserves in the form of gas hydrates.
EN
The technology of development of bottom gas-hydrate deposits, which allows to receive fresh water simultaneously with methane, is presented. Principal schemes are presented and methods of operation of dualpurpose plants implementing this technology and described on the basis of the methods of gas production from methane hydrates that are most prepared for practical implementation: 1) injection of warm water into the well; 2) depressive effect on the deposit; 3) replacement of methane in hydrates with carbon dioxide injected into the reservoir. The magnitude of the decrease in temperature with the depression effect on the deposit is determined. It is shown that, the amount of fresh water obtained in dual-purpose plants operating with the replacement of methane in hydrates with carbon dioxide is proportional to the coefficient of the recycling rate of CO2. For the considered schemes of dual-purpose plants, processes of decomposition of methane hydrates in the gas-hydrate formation are analyzed, an exergic efficiency estimation is performed. Such installations. The economic efficiency of a single-purpose and dual-purpose gas-producing units operating according to an approved method of depression is considered. It is shown that the most effective are dual-purpose facilities operating using the method of methane replacement in hydrates with carbon dioxide, and the coefficients of economic efficiency of dual-purpose installations are at least 1.2 times higher than similar coefficients of single-purpose gas production facilities.
EN
The majority of operations, as well as the physical and chemical processes, which take place on offshore Natural Gas installations are controlled by computer systems. These computer systems are vulnerable to cyber-attacks. If successful, such attacks can have disastrous and far-reaching consequences, including human casualties, large-scale pollution, and immense financial cost. In this paper we identify one possible way that an attacker can inflict material damage, by altering the parameters of the gas hydrate inhibition system. The formation of gas hydrates can completely halt operations for a prolonged period of time, could damage equipment, and directly endanger human lives. To raise the level of protection we propose the implementation of two lines of defense the second based on machine learning algorithms. Appreciating the sophistication of attacks, the inherent risks and complexity of multi-billion offshore energy assets we highlight the need for further research intended to address safety loopholes.
7
Content available remote Niekonwencjonalne węglowodorowe źródła energii – gazohydraty
PL
W artykule omówiono prace podejmowane w ostatnim okresie przez szereg krajów dla zlokalizowania złóż hydratów metanu, stanowiących źródło energii o zasobach prognostycznych wielokrotnie przewyższających wartości szacowane w przypadku złóż konwencjonalnych gazu ziemnego. Złoża hydratów występują w 98% na szelfach praktycznie wszystkich kontynentów, ale także w śródlądowych morzach i jeziorach czy pod pokrywą lodową stref podbiegunowych. Informacje o pozytywnych wynikach testu produkcyjnego, przeprowadzonego w 2013 r. przez japońską firmę JOGMEC, wzmogły intensywność tych poszukiwań, przy równoczesnym doskonaleniu techniki eksploatacji, tak aby były one bezpieczne, a wydobycie ekonomicznie uzasadnione.
EN
The article discusses the works undertaken recently by many countries aiming at finding deposits of methane hydrates which are a prognostic energy source exceeding several times the resources of conventional deposits of natural gas. Hydrate deposits occur in 98 per cent on the shelves of practically all continents, but also in inland seas and lakes, as well as under the ice caps of the polar zone. The news of positive results of production test carried out in 2013 by the Japanese company JOGMEC increased the intensity of exploration works and simultaneously contributed to improvements in production techniques so that they can be safe and the production economically substantiated.
EN
The problems of accumulation, transport and storage of gases and gas mixtures exist in many cases. Often the existent technologies appear ineffective for transporting his with pipelines, as condensate or compressed gas. Therefore, the transportation and storage of gas in hydrate form can be an alternative to traditional technologies. Preservation of gas hydrate blocks can store them for some time at the no equilibrium conditions. The thermodynamic parameters of forcibly conservation of gas hydrate blocks theoretically are determined and experimentally verified.
EN
Amplitude versus offset (AVO) analysis is a conventional seismic exploration technique in geophysical and lithological interpretation and has been widely used in onshore and offshore exploration. Its use in marine gas hydrate research, however, is still in initial stages. In this study, AVO analysis is applied to seismic profiles at drilling sites where hydrate samples have been recovered. The AVO responses of free gas, bottom simulating reflector (BSRs), and gas hydrates are discussed, and the AVO attributes in relation to gas hydrates are summarized. The results show that changes in intercept, gradient, fluid factor and Poisson’s ratio clearly reflect: (i) location of free gas and the BSR, and (ii) spatial relations between blank zone, BSR, gas hydrate, and free gas.
10
Content available remote Gazohydraty - nowy rodzaj paliw kopalnych
EN
Unconventional hydrocarbon resources in last years draw the attention of petroleum geologists. Significant position take the gas hydrates, first of all due to occurrences in many regions of the world and the size of the potential resources. These accumulations are localized in Arctic regions with permafrost as well as offshore. First gas hydrate discovery occurred in Siberian gas field Messoyakha in permafrost zone and similar accumulations were found in Alaska. Offshore occurrences are located mainly on continental slope. Drillings and samples from permafrost and seabed provided vast amount of data concerned conditions of gas hydrates formation and concentration and allow to better constrain the volume of hydrate-bearing sediments and their gas yield. Resources of hydrocarbons contained in gas hydrate deposits represent a vast energy source potential. Still essential problem is to elaborate efficient commercial production technology. So far positive developments regard only laboratory or semi-commercial scale.
EN
It is shown that the known reserves of marine minerals, including polymetallic nodules hydrates, marine sapropels, etc., will last the humanity for thousands of years. International cooperation and broad cooperation of companies and enterprises of maritime mining are needed to conduct the search, along with research and operation of deep mining complexes. This will allow us to prepare for the commercial development of marine deposits of mineral and energy resources in the near future.
EN
In this paper, gas pipeline optimization includes constraints resulting from hydrate prevention. The key is to seek for the optimal settings of both: the compressor units and hydrate combating method at minimum fuel consumption subject to security of supply and hydrate prevention. A case study is conducted on the Polish section of the Yamal pipeline and an arbitrarily selected partial onshore and offshore pipeline. Three different configurations are investigated: (i) cooling the compressed gas, (ii) no cooling and (iii) line heating immediately after the compressor station. For each configuration, the fuel consumption of the compressors is minimized and in order to prevent hydrate formation, the outlet temperature of the line heater, allowable water vapour in the gas and methanol concentration are calculated for each pipe section. The hydrate model is based on the statistical mechanical approach of Van der Waals and Platteeuw and applicable for systems that contain water (free or dissolved in gas), methanol and mixed gases both hydrate and non-hydrate formers.
PL
W artykule omówiono zagadnienie optymalizacji gazowego systemu przesyłowego uwzględniając dodatkowo ograniczenia wynikające z warunków tworzenia się hydratów. Kryterium optymalizacji to minimum zużycia paliwa w tłoczniach gazu. Badania przeprowadzono na polskiej części gazociągu jamalskiego dla trzech przypadków pracy tłoczni: chłodzenie gazu w tłoczni, brak chłodzenia oraz podgrzewanie gazu za stacją przetłoczną. Dla każdego wariantu, zużycie paliwa przez sprężarki jest minimalizowane oraz w celu przeciwdziałania tworzenia się hydratów, temperatura wyjściowa podgrzewacza jest obliczana a także obliczana jest zawartość pary wodnej i metanolu w gazie dla każdej sekcji gazociągu. Zastosowany model hydratu jest oparty na modelu Van der Waalsa oraz Platteeuw.
EN
The paper put forward the idea of sampling for gas hydrates by hole bottom freezing, and the method is that the temperature of the gas hydrate core is decreased on the hole bottom by cold source, the result of decreasing the temperature is the same as increasing pressure to inhibit gas hydrate dissociating and retains the core of gas hydrates. Firstly, the feasibility of hole bottom freezing method for sampling gas hydrates is analysed by research the temperature-pressure property. Secondly, it is confirmed that the dry ice is used as coolant, the alcohol as positive freezing catalyst and cooling medium by the indoor freezing experiment. Finally, the freezing sample tool is developed, the freezing loess sample is achieved. The research supplies the news ideas for the design of gas hydrates core sampler.
PL
Zaprezentowano ideę opróbowania hydratów gazowych przy zastosowaniu zamrażania dna otworu. Polega ona na tym, że temperatura rdzeniowanego materiału jest obniżana w dnie otworu, co wywołuje podobny efekt jak wzrost ciśnienia, uniemożliwając dysocjację pobieranych próbek hydratów. Zaproponowano użycie suchego lodu jako czynnika chłodzącego oraz alkoholu jako katalizatora procesu zamrażania. Przedstawiono nowe możliwości projektowania rdzeniówek do poboru próbek hydratów.
EN
Gas hydrates - the firm crystal connections formed water (liquid water, an ice, water vapor) and low-molecular waterproof natural gases such as carbohydrates (mainly methane), CO2, N2 and others, whose crystal structure effectively compresses gas: each cubic meter of hydrate can yield over 160 m3 of methane. The current estimates show that the amount of energy in these gas hydrates is twice total fossil fuel reserves, indicating a huge source of energy, which can be exploited in the right economical conditions. The further perfection of prospecting methods in the field of studying gas hydrate containing sediments in round extent depends on improvement of methods of sampling native-state core from these sediment keeping not only original composition, but structural - textural features of their construction. A pressure and temperature core sampler comprises a tool for recovering cores specifically enabling the evaluation of methane hydrate resources. Because methane hydrate tends to decompose under conditions of pressure decrease and/or temperature increase as the samples are retrieved to the surface, a coring tool in accordance with the present invention provides a self-contained system for retrieving core samples at or near in situ conditional. The coring tool is preferably a wire line retrievable device that provides for nearly continuous coring during the drilling operation. In present time for sampling native-state core in natural gas hydrates deposits we are development the sampling device using the effect conservation gas hydrates at negative temperature conditions.
15
Content available Wykorzystanie zjawiska hydratacji gazów
EN
Gas hydrates (clathrate hydrates) forms non-stoichiometry solid solutions compose with condensed hydrate substances closed into water crystalline lattice. Clathrates are not chemical compounds, because lattice of water crystal is stabilized by hydrogen bonds, while van der Waals forces answer for water molecules and hydrate substances influences. Their specific physical properties are utilize in various industrial fields, mainly in natural gas industry, because methane hydrate have the greatest importance. Fundamental task are now is preventing of hydrates formation in production chain (production, storage, transportation) of natural gas and crude oil, that is why to research of new prevention methods, mainly various inhibitors (kinetic, thermodynamic, dispersive, mixed) and modifiers. Many countries intensively research of storage and transport of natural gas in the hydrate form, with regard to stability in room temperature, quite low pressure and the possibility of high pressure generation without compressor application. Many researches are about surfactants which accelerate hydrates growth. Next technologies concern of purification and/or separating sour gases (carbon dioxide, hydrogen sulfide) from natural gas and synthetic gas (hydrogen + carbon oxide). Hydrate formation method allows to selectively separation one component from the mixture and distribution of boilingnear substances as well. Hydrate formation phenomenon is make use of desalinate sea water, paper production, food production, heat storage, and sequestration of carbon dioxide on the sea bed. Water vapor pressure over hydrates is lower than over pure water, which enable to gas drying. More often is thinking of methane production from huge deposits of methane hydrates. Production from deposit rest on destabilization methane through well known conditionings from pipelines unpluging 1) adding strong hydrogen bonds chemical substances (inhibitor), 2) increasing temperature of deposit using water vapor or hot water and gas production through another well, 3) pressure decrease in the well below stability point of hydrate formation and bottom plant to hydrates gathering from the sea bed and transport equipment onto the ship. However, above- mentioned proposals will be hard to carry out on to large scale in case of technical, economical and environmental reasons.
PL
Hydraty gazów (gazo-hydraty, klatraty, hydraty klatkowe) tworzą niestechiometryczne stałe roztwory składające się ze skondensowanych substancji "hydratotwórczych" zamkniętych w sieci krystalicznej wody. Klatraty nie są związkami chemicznymi, ponieważ sieć kryształu wody stabilizują wiązania wodorowe, natomiast za oddziaływania molekuł wody i substancji hydratotwórczej odpowiadają siły van der Waalsa. Ich specyficzne fizyczne właściwości wykorzystuje się w różnych dziedzinach przemysłu, głównie w przemyśle gazowniczym, ponieważ największe znaczenie ma powszechnie występujący hydrat metanu. Obecnie podstawowym zadaniem jest zapobieganie wytracaniu się hydratów w łańcuchu eksploatacyjnym (wydobycie, magazynowanie i transport) gazu ziemnego i ropy naftowej, dlatego bada się nowe metody prewencyjne, głównie różne inhibitory (kinetyczne, termodynamiczne, dyspersyjne, mieszane) i modyfikatory. Intensywnie bada się w wielu krajach magazynowanie i transport gazu ziemnego w formie hydratów, ze względu na temperatury pokojowe, w miarę niskie ciśnienia oraz możliwość wytworzenia wysokiego ciśnienia bez stosowania sprężarek. Wiele badań poświęcone jest surfaktantom przyspieszającym wzrost hydratów. Kolejne technologie dotyczą oczyszczania lub/i separacji gazów kwaśnych (dwutlenek węgla, siarkowodór) z gazu ziemnego i gazu syntezowego (wodór + tlenek węgla). Również metoda hydratacji pozwala na selektywną separację składnika mieszaniny oraz rozdział blisko wrzących substancji. Zjawisko hydratacji wykorzystuje się do odsalania wody morskiej, w produkcji papieru, w technologii żywności, jako magazyny ciepła, czy sekwestracji hydratu dwutlenku węgla na dnie oceanu. Prężność pary wodnej nad hydratami jest niższa niż nad czystą wodą, co pozwala na osuszania gazu. Coraz częściej myśli się o pozyskaniu metanu z ogromnych złóż hydratu metanu. Wydobycie metanu ze złoża polega na jego destabilizacji poprzez znane już uwarunkowania z prewencji w gazociągach 1) dodanie substancji chemicznych o silnych wiązaniach wodorowych (inhibitory), 2) podwyższenie temperatury złoża za pomocą pary wodnej lub gorącej wody i odpompowanie gazu na powierzchnię morza przez inny odwiert, 3) obniżenie ciśnienia w odwiercie poniżej punktu stabilności hydratu oraz urządzenia denne do zbierania hydratów z dna morskiego wraz z przewodowym transportem na statek. Powyższe propozycje będą jednakże trudne do zrealizowania na dużą skalę ze względów technicznych, ekonomicznych i środowiskowych.
16
Content available remote Odsiarczanie gazu ziemnego metodą hydratacji
PL
Podstawowe składniki kwaśnego gazu ziemnego: metan, dwutlenek węgla i siarkowodór, w obecności wody w odpowiednich warunkach ciśnienia i temperatury tworzą hydraty gazowe. Obecnie hydraty gazowe sa obiektem zainteresowań w wielu dziedzinach, w tym: w transporcie i magazynowaniu gazu ziemnego, w procesach chłodniczych i "magazynach zimna", w sekwestracji ditlenku węgla, w procesach rozdzielania i do innych zastosowań. Celem niniejszego artykułu jest literaturowy przegląd technologii, badań i podstawowych informacji koniecznych do opisu zjawiska hydratacji siarkowodoru w mieszaninie kwaśnych gazów ziemnych. Większość badań związana jest z problematyką ochrony środowiska i dotyczy zmniejszania ilości ditlenku węgla uwalnianego do atmosfery. W takim przypadku, procesy separacji składników oparte o metodę hydratacji gazów dotyczą jednocześnie obu kwaśnych składników gazu ziemnego (siarkowodoru i ditlenku węgla) i muszą być badane wspólnie i jednocześnie. Informacje o tych warunkach są również niezbędne dla przemysłu gazowniczego; do celów konstrukcyjnych i procesowych dla instalacji gazowniczej i rurociągów.
EN
Main components of the sour natural gas, such as methane, carbon dioxide and hydrogen sulfide form gas hydrates in presence of water and under suitable temperature and pressure conditions. Gas hydrates are now renewed interest in many fields, includes: natural gas storage and transportation, in refrigeration processes and cool storage, sequestration of carbon dioxide, separation processes and many others. The purpose of this paper is to briefly literature review of projects, research, and basic information needed for description of the hydrogen sulfide hydrate formation in sour natural gas mixtures. The most studies concern reducing the quantities of carbon dioxide released into the atmosphere, as a major environmental challenge. In this case, a separation processes dealing with hydrate formation both sour compounds (hydrogen sulfide and carbon dioxide) of natural gas mixture have to be treated commonly and simultaneously. Information on such conditions is also vital to the natural gas industry to design and operate processing equipment and pipelines.
EN
Global warming caused by increased emissions of greenhouse gases (especially carbon dioxide) to the atmosphere can be accelerated by release of additional amounts of methane from gas hydrates. These specific chemical compounds (clathrates) consisting of water and hydrocarbons exist as solids under a narrow range of conditions. The methane hydrates occur naturally mainly in the ocean bottom worldwide, as well as on lands in the permafrost zone. The last decade of the 20th century expanded our knowledge on areas of occurrence, potential resources, environmental conditions of gas hydrate formation and their stability. Increasing average temperature of the Earth changes the conditions of gas hydrate stability and may result in release of methane into seawater and then atmosphere. This may intensify the greenhouse effect. Thus, international research centres should urgently develop an integrated effort towards studying the origin and areas of occurrence of the gas hydrates, as well as feasibility of their commercial exploitation. Such integration could be coordinated by the International Sea Bed Authority within the proposed Project HOPE (Hydrates in Oceans - Program of Explorations).
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